This invention relates to a bidirectional rotation device and more particularly relates to an electromechanical bidirectional rotation device applicable for controlling a variety of mechanical apparatuses.
In electromechanical control apparatuses, it is often required to control a mechanical componet such as a baffle, interlock or the like between two positions selectively and alternately. For example, in the conduction of a gaseous material from one location to another location, a baffle plate is provided in the conducting pipe so that the baffle can be pivoted to position either parallel to the longitudinal axis of the pipe to allow the gas to flow through the pipe or transverse to the longitudinal axis thus blocking the flow of gas through the pipe. An electromechanical system is commonly employed to provide the positioning of such baffle. The baffle is connected to a mechanical pivotting linkage outside of the pipe, and the linkage is coupled to an electromagnetic solenoid. The solenoid can be energized to push the linkage in a direction to position the baffle at the selected position accordingly. In such system, a biassing means such as a biassing spring must be provided to return the baffle to the first position when the solenoid is de-energized. It can be appreciated that the solenoid must be of such size that sufficient strength is generated therein to overcome the force of the biassing spring initially in order to pivot the baffle to the selected blocking position. Furthermore, in order to maintain the baffle in the blocking position, the solenoid must remain energized. Thus, it is not energy efficient to operate such system. Moreover, such solenoid system requires a relatively high voltage to operate. Therefore, it is not suitable for use, particularly, in a low voltage system. For a low voltage system, complex electrical control is usually required to provide sufficient torque to operate the mechanical component. Also, in such electromechanical arrangement, the mechanical linkage is often subject to breakdown after a relatively short period of time in use.